HYBRID CONTROL SYSTEM, Diagnostic DTC:P0C73-776

Info Added 2017-08-02

DTC Code DTC Name
P0C73-776 Motor Electronics Coolant Pump "A" Control Performance

DESCRIPTION

The inverter water pump assembly transmits rotation revolution speed information to the power management control ECU. The power management control ECU monitors the revolution speed and detects malfunctions.

DTC No. INF Code DTC Detection Condition Trouble Area
P0C73 776

The inverter water pump assembly revolution speed is abnormally high or low (or stop) for 1 minute or more or the inverter water pump assembly stops intermittently after abnormal revolution speed is detected.

(1 trip detection logic)

  • Inverter cooling system

  • Wire harness or connector

  • Inverter water pump assembly

  • Power management control ECU

Tech Tips

The inverter water pump assembly operates when the power switch is on (READY).

Related Data List
DTC No. Data List Item
P0C73-776

  • Inverter Coolant Water Temperature

  • W/P Run Control Duty*1

  • Inverter W/P Revolution

  • Ready Signal

*1: This Data List item is related to the inverter water pump assembly.

Related Active Test
DTC No. Active Test
P0C73-776 Activate the Water Pump*2

*2: This is an Active Test of the inverter water pump assembly.

WIRING DIAGRAM

B001VCUE09

CAUTION / NOTICE / HINT

Note


  • If DTC P0A78-284, 286, P0A7A-322, 324, P0A94-553 or 557 is output, replace the inverter with converter assembly after this inspection.

  • In the case of a coolant leak, the inverter water pump assembly activates a fail-safe function. If the inverter water pump assembly is not the cause of the coolant leak, it is not necessary to replace it.

Tech Tips

After the repair, clear the DTCs and perform the following procedure to check that DTCs are not output.


  1. Turn the power switch on (READY) and wait for 2 minutes or more.

PROCEDURE


  1. CHECK QUANTITY OF HV COOLANT


    1. Check the HV coolant level in the inverter reserve tank.

    2. Check for HV coolant leaks.

      Result
      Result Proceed to
      No leaks are found and coolant level in the inverter reserve tank assembly is above the low line. A
      No leaks are found and coolant level in the inverter reserve tank assembly is below the low line. B
      HV coolant leaks are evident. C

      Tech Tips

      After repairing the HV coolant leaks and adding coolant, perform the "Activate the Water Pump" Active Test (HV Active Test item) and the "Control the Electric Cooling Fan" Active Test (Engine Active Test item) and make sure that there are no malfunctions.


    B

    ADD HV COOLANT

    C

    INSPECT FOR HV COOLANT LEAK

    A

  2. CHECK COOLANT HOSE


    1. Check if the hoses of the cooling system are kinked or clogged.


    NG

    CORRECT THE PROBLEM

    OK

  3. READ VALUE USING GTS (INVERTER W/P REVOLUTION)

    Note

    Be sure to perform the inspection with the auxiliary battery voltage at 11 V or more.

    Tech Tips


    • When the auxiliary battery voltage is low, the inverter water pump assembly may not operate.

    • When the inverter water pump assembly signal line (SWP - IWP) is open or its connection is faulty, the inverter water pump assembly is operated forcibly.


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Data List / Inverter W/P Revolution.

    4. Read the Data List.

      Result
      Tester Display Condition Specified Condition
      Inverter W/P Revolution Power switch on (IG) 625 rpm or less

      Tech Tips

      When the inverter water pump assembly is not operating, the Data List item "Inverter W/P Revolution" usually displays 625 rpm continuously.

    5. Turn the power switch off.


    NG

    CHECK CONNECTOR CONNECTION CONDITION (POWER MANAGEMENT CONTROL ECU CONNECTOR) Click here

    OK

  4. CLEAR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

    4. Read and record the DTCs and freeze frame data.

    5. Clear the DTCs and freeze frame data.

    6. Turn the power switch off.


    NEXT

  5. PERFORM ACTIVE TEST USING GTS (ACTIVATE THE WATER PUMP)

    Note

    Be sure to perform the inspection with the auxiliary battery voltage at 11 V or more.

    Tech Tips

    When the auxiliary battery voltage is low, the inverter water pump assembly may not operate.


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Active Test / Activate the Water Pump.

    4. Select Inverter W/P Revolution in the Data List.

    5. While performing the "Activate the Water Pump" Active Test, check Inverter W/P Revolution in the Data List.

      Result
      Tester Display Condition Specified Condition
      Inverter W/P Revolution

      Power switch on (IG)

      During Active Test

      		 2500 to 5875 rpm

      Tech Tips


      • Perform the Active Test with the inverter coolant temperature between -15 and 65°C (5 to 149°F).

      • When the inverter water pump assembly is not operating, the Data List item "Inverter W/P Revolution" usually displays 625 rpm continuously.

    6. Turn the power switch off.


    NG

    CHECK CONNECTOR CONNECTION CONDITION (POWER MANAGEMENT CONTROL ECU CONNECTOR) Click here

    OK

  6. CHECK HV COOLANT (CHECK FOR CONDITIONS THAT MAY HAVE CAUSED FREEZING)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

    4. Read the freeze frame data Ambient Temperature using the GTS.

    5. Check if the freeze frame data Ambient Temperature is below freezing.

      Result
      Result Proceed to
      Ambient Temperature value is above freezing temperature of the HV coolant. A
      Ambient Temperature value is below freezing temperature of the HV coolant. B

      Tech Tips


      • HV coolant (SLLC) with a 30% concentration freezes at -15 °C (5°F) and HV coolant (SLLC) with a 50% concentration freezes at -35°C (-31°F).

      • If the HV coolant freezes in the HV radiator or HV water pump, the coolant temperature in the inverter with converter assembly rises because the HV coolant cannot circulate. As a result, a DTC may be stored.

      • A DTC is stored when the water pump impeller cannot rotate due to freezing of the HV coolant.

      • If a DTC is stored due to freezing of HV coolant, the problem cannot be reproduced. Judge whether freezing of HV coolant occurred according to the freeze point of the HV coolant, HV coolant change history and ambient temperature when the DTC was stored.

    6. Turn the power switch off.


    A

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    B

    REPLACE HV COOLANT Click here

  7. CHECK CONNECTOR CONNECTION CONDITION (POWER MANAGEMENT CONTROL ECU CONNECTOR)


    1. A0005OEE01
      Text in Illustration
      *A for LHD
      *B for RHD

      Check the connector connections and contact pressure of the relevant terminals for the power management control ECU connectors Click here.

      OK
      The connectors are connected securely and there are no contact pressure problems.

    NG

    CONNECT SECURELY

    OK

  8. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WATER PUMP ASSEMBLY CONNECTOR)


    1. B001VI2

      Check the connector connections and contact pressure of the relevant terminals for the inverter water pump assembly connector Click here.

      OK
      The connectors are connected securely and there are no contact pressure problems.

    NG

    CONNECT SECURELY

    OK

  9. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - INVERTER WATER PUMP ASSEMBLY)


    1. Disconnect the A31 power management control ECU connector.

    2. Disconnect the A41 inverter water pump assembly connector.

    3. Measure the resistance according to the value(s) in the table below.

      B001VGRE03
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      		 *b

      Front view of wire harness connector

      (to Inverter Water Pump Assembly)
      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A31-13 (IWP) - A41-3 (SWP) Power switch off Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A31-13 (IWP) or A41-3 (SWP) - Body ground and other terminals Power switch off 10 kΩ or higher

    4. Reconnect the A31 power management control ECU connector.

    5. Reconnect the A41 inverter water pump assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. READ VALUE USING GTS (INVERTER W/P REVOLUTION)

    Note

    Be sure to perform the inspection with the auxiliary battery voltage at 11 V or more.

    Tech Tips

    When the auxiliary battery voltage is low, the inverter water pump assembly may not operate.


    1. Connect the GTS to the DLC3.

    2. Remove the INV W/PMP fuse from the No. 2 engine room relay block.

    3. Turn the power switch on (IG).

    4. Enter the following menus: Powertrain / Hybrid Control / ECU Data List / Inverter W/P Revolution.

    5. Read the Data List.

      Result
      Tester Display Condition Specified Condition
      Inverter W/P Revolution Power switch on (IG) 125 rpm or less

    6. Turn the power switch off.

    7. Install the INV W/PMP fuse.


    NG

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    OK

  11. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - INVERTER WATER PUMP ASSEMBLY)


    1. Disconnect the A31 power management control ECU connector.

    2. Turn the power switch on (IG).

    3. B001VBAE03
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      A31-13 (IWP) - H1-6 (E1) Power switch on (IG) 11 to 14 V

      Note

      Turning the power switch on (IG) with the power management control ECU connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

    4. Turn the power switch off.

    5. Reconnect the A31 power management control ECU connector.


    NG

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    OK

  12. CHECK POWER MANAGEMENT CONTROL ECU (CHECK WAVEFORM)


    1. Turn the power switch on (IG).

    2. B001VGZE03
      Text in Illustration
      *a

      Component with harness connected

      (Power Management Control ECU)

      While turning the power switch on (IG), check the waveform between the power management control ECU terminals.

      Item Content
      Terminal A31-13 (IWP) - H1-6 (E1)
      Equipment Setting 5 V/DIV., 50 ms./DIV.
      Condition Power switch on (IG)
      OK
      Waveform duty ratio is between 3% and 9%.

    3. Turn the power switch off.


    OK

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    NG

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

  13. REPLACE HV COOLANT


    1. Replace the HV coolant with coolant having an appropriate concentration (appropriate freeze point) for the vehicle usage conditions Click here.


    NEXT

    COMPLETED